1. Topological properties of fuzzy numbers;Goetschel;Fuzzy Sets and Systems,1983
2. Elementary fuzzy calculus;Goetschel;Fuzzy Sets and Systems,1986
3. Introduction to Fuzzy Arithmetic: Theory and Applications;Kaufmann,1985
4. Differentials for fuzzy functions;Puri;J. Math. Anal. Appl.,1983
5. General Theory of Functions and Integration;Taylor,1965